In general, a battery connector (i.e., a connector contained in a battery pack) that is built in a portable telephone is designed to make mating connection with a board attachment type electrical connector (hereafter referred to simply as “electrical connector”) that is mounted on a circuit board on the side of the main body of the portable telephone.
The electrical connector 101 shown in FIG. 11 (see JP2000-235878A), for example, has been conventionally known as an electrical connector of the board attachment type.
This electrical connector 101 comprises a housing 110 that is mounted on a circuit board PCB and a plurality of contacts 120 that are attached to this housing 110. Furthermore, each of the contacts 120 comprises a substantially rectangular base plate part 121, a press-fitting fastening part 122 that extends upward from the base plate part 121 and that is press-fitted to the housing 110, and a contact part 123 that extends forward from the upper portion of the front end (right end in FIG. 11) of the base plate part 121. Each contact part 123 is formed with a flat plate-shaped tab, and protrudes further to the front than the front-end surface of the housing 110 so that both main surfaces are perpendicular to the direction in which the contacts 120 are aligned (direction perpendicular to the plane of the page in FIG. 11). Moreover, a board connecting part 124 that is connected by soldering to the circuit board PCB extends downward from the lower portion of the rear end of each base plate part 121.
Furthermore, the electrical connector 101 mates with a mating battery connector 130. As a result, the contact parts 123 of the contacts 120 are accommodated by the mating contacts 131 of the mating battery connector 130, and make contact therewith, thus electrically connecting the circuit board PCB and the battery.
Moreover, the electrical connector shown in FIG. 12 (see JP2002-134196A), for example, has also been known as another electrical connector that makes mating connection with a mating battery connector.
This electrical connector 201 comprises a housing 210 that is mounted on a circuit board (not shown in the figure) and a plurality of contacts 220 that are attached to this housing 210. Furthermore, each of the contacts 220 comprises a press-fitting fastening part 221 that is press-fitted to the housing 210, a contact part 222 that extends upward from the press-fitting fastening part 221 and that makes contact with a corresponding mating contact (not shown in the figure), and a board connecting part 223 that extends downward from the press-fitting fastening part 221 and that is connected by soldering to the circuit board (not shown in the figure). Each contact part 222 is formed with a flat plate-shaped tab, and protrudes further upward than the upper-end surface of the housing 210 so that both main surfaces are perpendicular to the direction of alignment of the contacts 220 (left-right direction in FIG. 12). The electrical connector 201 mates with a mating battery connector (not shown in the figure). As a result, the contact parts 222 of the contacts 220 are accommodated by the mating contacts of the mating battery connector, and make contact therewith, so that the circuit board and the battery are electrically connected.
However, with these electrical connectors 101 and 201, for instance, in cases where an impact is applied in a direction perpendicular to the main surfaces of the contact parts 123 and 222 by the dropping or the like of portable telephones that contain the electrical connectors 101 and 201, there is a danger that the housings 110 and 210 and contacts 120 and 220 will be damaged since the contact parts 123 and 222 are not movable.
In order to handle this problem, the electrical connector shown in FIG. 13 (see JP06-44063U), for example, has been known as an electrical connector in which contact parts are designed to be movable.
This electrical connector 301 comprises a first housing 310 that is mounted on a circuit board (not shown in the figure), a second housing 320 that is located on the upper surface of the first housing 310, and a plurality of contacts 330.
Here, each of the contacts 330 comprises a first press-fitting part 331 that is press-fitted into a press-fitted fastening passage 321 in the second housing 320, a contact part 332 that extends forward (toward the left in FIG. 13) from the first press-fitting part 331, a second press-fitting part 334 that is press-fitted into a press-fitted fastening hole 311 in the first housing 310, a flexible connecting part 333 that connects the first press-fitting part 331 and the second press-fitting part 334, and a board connecting part 335 that extends downward from the second press-fitting part 334. Each flexible connecting part 333 is formed into a structure that extends in the vertical direction and is bent forward and rearward; the lower portion of the flexible connecting part 333 is located inside a first cavity formed in the first housing, and the upper portion of the flexible connecting part 333 is located inside a second cavity 322 formed in the second housing 320. The first and second press fitting parts 331, 334 are in the form of a fastening plate.
Each contact part 332 is formed with a flat plate-shaped tab, and protrudes forward so that both main surfaces are perpendicular to the direction of alignment of the contacts 330 (direction perpendicular to the plane of the page in FIG. 13). Moreover, each contact part 332 protrudes downward from the lower surface of the first housing 310 and is connected by soldering to a circuit board (not shown in the figure). Furthermore, each of the contact parts 332 is constructed so that free play is possible with respect to the board connecting part 335 by means of the flexible connecting part 333 that connects the first press-fitting fastening plate part 331 and the second press-fitting part 334, thus allowing the movement in the rearward direction indicated by arrow X in FIG. 13, the movement in the forward direction indicated by arrow Y, the movement in the upward direction indicated by arrow Z, and the movement in the direction of alignment of the contacts 330.
Accordingly, in cases where an impact is applied in the direction perpendicular to the main surfaces of the contact parts 332 (i.e., in the direction of alignment of the contacts 330), since the contact parts 332 can move in this direction, it is possible to avoid the danger of damaging the first housing 310, second housing 320 or contacts 330.
However, the following problems have been encountered in the electrical connector 301 shown in FIG. 13:
Specifically, in order to increase the free play of the contact parts 332 with respect to the board connecting parts 335, it is necessary to increase the flexibility of the flexible connecting parts 333, and in order to increase the flexibility of these flexible connecting parts 333, it is necessary to increase the total length of these flexible connecting parts 333. However, since each of the flexible connecting parts 333 is formed into a structure that extends in the vertical direction and is bent forward and rearward in the same plane as the contact part 332, in order to increase the total length of the flexible connecting part 333, the width must be reduced, so that a large current (maximum of approximately 3 A) cannot be caused to flow. The width of the flexible connecting parts 333 of the electrical connector 301 shown in FIG. 13 is smaller than the width of the board connecting parts 335, so that a large current cannot be caused to flow.